“The key trick here is that the small differences in the proteins that make up different forms of amyloid interact differently with our fluorescent probes to result in measurably different colors of the emitted light,” says study researcher Jerry Yang of UCSD.

The colors vary depending on the physical properties of pockets in the different amyloid proteins:

They glow green when it binds to amyloids associated with Alzheimer’s disease in tissue samples (pictured, below).

Diagnostics that can distinguish between different, but closely related diseases – especially those where symptoms and pathological characteristics show many similarities – would be very important for deciding on effective treatment strategies for specific diseases.

By using an ointment or eye drops loaded with these fluorescent markers, doctors could light up amyloids in the eye in different colors. The technology has been licensed for commercial development of diagnostic tests for human neural disease.

The study is published in the Journal of the American Chemical Society this week.